Jump-Starting 12V Battery Charger PSA

[TMYB-C1]

This following might have been mentioned in this this thread. The battery can fail in multiple ways shorted cell, bad cell, case cracked etc. Leaving the jumpstarter connected for 10 minutes might work but it might also discharge it to the point where you are stranded. Not knowing what the problem is, I would disconnect the negative battery cable and attach the jumpstarter. After the contactors close and the DC-to-DC converter is enabled, the car does not require a 12V source. Remove the jumpstarter after the car is awake/operational. Turn on sentry mode so the car does not go back to sleep until you get home/replace the battery. I responded to another thread in this forum a while back with the suggestion to remove the negative cable and it worked for the owner. If anyone sees a flaw using this procedure or something that might cause further damage please respond.

A23 battery in pocket, jumpstarter and 10MM wrench in frunk. Note: most jumpstarters require a minimum voltage they use to detect reverse polarity; therefore, you need to know how to manually enable the voltage output on the unit you own/purchase.

A23 battery in pocket, jumpstarter and 10MM wrench in frunk is exactly what I plan to do after reading through this thread, thanks all for the input. I haven't had any issues with my battery, but would like to be prepared if this does happen.

 

[HtownMY9999]

This is just a public service announcement regarding what to use to jump start the Model 3 12V battery if it dies. Most of you know if the 12V battery dies, all windows and frunk and trunk closes and you cannot get into the car with your phone or key card, nor be able to access the car with your Tesla app. Most of you also know how to open the frunk using the tow hole cables and hooking up a 12V battery to them.

This happened to me recently, and while I was able to open the frunk using the method above (using a trickle charger), I did not want to jump start the battery due to reports of potentially damaging any car that you use to jump start it (or damage to the Tesla), or physically taking out the battery and replacing it due to the complexity of taking off the rear passenger seat to uncouple the 12V from the main battery. I also wasn't sure which portable or wheeled jump charger to use, for the same potential damage reasons.

So I called Tesla Roadside and a tow truck came out. The tow driver used a TopVision jump charger on the 12V, and the car instantly charged up, doors opened, and systems came back on.

Here is the model he used. Note that I have no proprietary interest in any of the products or companies, I just wanted to share:

Amazon.com

One question: I would love to store the above jump charger in the frunk for any potential recurrence of the above situation, but the irony is that one needs a 12V charger (it used to be 9V, but no more) to open the frunk first. Any ideas on a work-around to make this idea work?

-Slipstream

The link you shared for the model of TopVision Jump charger isn’t working for me. Can you share the full name or new link.
TIA.

 

[Slipstream]

The link you shared for the model of TopVision Jump charger isn’t working for me. Can you share the full name or new link.
TIA.

Here you go:
ZW5jcnlwdGVkUXVhbGlmaWVyPUFCS0JOWEhBUkgwVzgmZW5jcnlwdGVkSWQ9QTA5OTQzMjMySEhJVDgyNTNLWjdFJmVuY3J5cHRlZEFkSWQ9QTAxNTE4MjQyRVc4SThSODJZRUtJJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ

 

[Slipstream]

Here you go:
https://www.amazon.com/TOPVISION-LI...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

 

[Resist]

Revising an old thread. My 2018 Model 3 LR 12 volt has never been replaced and seems fine. I did buy a portable lithium jump starter, that I keep in my trunk. I also have a battery is plastic bag behind the front tow hook cover, to get into the frunk. Can someone explain step by step how to use the jump starter on my 12 volt battery, should it die on me and I need to get home. Obviously if it did die I would be getting a replacement 12 volt battery.

 

[davewill]

Revising an old thread. My 2018 Model 3 LR 12 volt has never been replaced and seems fine. I did buy a portable lithium jump starter, that I keep in my trunk. I also have a battery is plastic bag behind the front tow hook cover, to get into the frunk. Can someone explain step by step how to use the jump starter on my 12 volt battery, should it die on me and I need to get home. Obviously if it did die I would be getting a replacement 12 volt battery.

You might want to put that jumper pack in the frunk. If the battery is dead you might not be able to get the trunk open. With most of those lithium jumper packs, you connect the positive and negative leads to the battery, then push the "On" button to start. Because it's not powered when you're connecting, the order you connect isn't really important.

 

[Resist]

You might want to put that jumper pack in the frunk. If the battery is dead you might not be able to get the trunk open. With most of those lithium jumper packs, you connect the positive and negative leads to the battery, then push the "On" button to start. Because it's not powered when you're connecting, the order you connect isn't really important.

I thought about that but the Frunk will get way hotter inside during the summer than in the bottom trunk. Plus I have a battery behind the tow cover, so I could still get the car opened. And yes I know how the lithium jumper pack works, I was more concerned with having to do anything special with the Tesla prior to using the jumper. But with my Lithium jumper you connect the cables to the battery first and then plug it into the jumper pack, no pressing a button. I know the lithium jumper isn't charging up the 12 volt battery, especially if it's completely dead and won't hold a charge. The jumper is just providing juice so the computer senses power and then turns the car on. Some people think these jumpers actually charge an ICE vehicles battery, but that's not true as they really are just giving enough power so the starter motor runs to get the engine started and then the alternator takes over providing electrical power.

 

[android04]

I thought about that but the Frunk will get way hotter inside during the summer than in the bottom trunk. Plus I have a battery behind the tow cover, so I could still get the car opened. And yes I know how the lithium jumper pack works, I was more concerned with having to do anything special with the Tesla prior to using the jumper. But with my Lithium jumper you connect the cables to the battery first and then plug it into the jumper pack, no pressing a button. I know the lithium jumper isn't charging up the 12 volt battery, especially if it's completely dead and won't hold a charge. The jumper is just providing juice so the computer senses power and then turns the car on. Some people think these jumpers actually charge an ICE vehicles battery, but that's not true as they really are just giving enough power so the starter motor runs to get the engine started and then the alternator takes over providing electrical power.

You need to put the jump starter pack in the frunk. Jumping the two wires behind the tow hook cover will not unlock the car, it just pops open the frunk. You won't be able to get inside the doors or the trunk without jump starting the car.

I've carried my lithium ion jump starter in my frunk for the last 4.5 years. Your jump pack should be rated for hot temperatures inside a car and the temperature in the frunk should not affect it. It should actually get hotter inside the car due to the glass and the greenhouse effect. The frunk will probably not get much hotter than ambient temperature, which should be fine for the jump pack battery.

 

[dmurphy]

I thought about that but the Frunk will get way hotter inside during the summer than in the bottom trunk. Plus I have a battery behind the tow cover, so I could still get the car opened. And yes I know how the lithium jumper pack works, I was more concerned with having to do anything special with the Tesla prior to using the jumper. But with my Lithium jumper you connect the cables to the battery first and then plug it into the jumper pack, no pressing a button. I know the lithium jumper isn't charging up the 12 volt battery, especially if it's completely dead and won't hold a charge. The jumper is just providing juice so the computer senses power and then turns the car on. Some people think these jumpers actually charge an ICE vehicles battery, but that's not true as they really are just giving enough power so the starter motor runs to get the engine started and then the alternator takes over providing electrical power.

Have you actually tried popping the trunk with the small 12V batt? I haven’t seen it work - amperage appears to be too low.

 

[android04]

Have you actually tried popping the trunk with the small 12V batt? I haven’t seen it work - amperage appears to be too low.

I also carry an A23 battery in a ziplock bag behind my toe hook cover (it's a tiny 12v battery) and it does work to open the frunk. I've tried it multiple times in 2 different years and it works fine. Keep in mind that this test will only work if the doors are unlocked, or if your car's 12v battery is dead.

 

[dmurphy]

I also carry an A23 battery in a ziplock bag behind my toe hook cover (it's a tiny 12v battery) and it does work to open the frunk. I've tried it multiple times in 2 different years and it works fine. Keep in mind that this test will only work if the doors are unlocked, or if your car's 12v battery is dead.

I'll have to kill my 12V lead-acid and give it a shot. I tried it a few weeks ago on a car in the shop and it didn't do anything - didn't actuate the frunk release at all... Not sure if there was something else wrong, however.

I'll have to give it another try. Thank you!

 

[KenC]

Yep, an A23 behind the two hook cover, and yes to a NOCO in the frunk. Has anyone put a thermometer in the frunk to test out the temperature potential? How about if you put an underhood fabric liner?

 

[Randy-12]

You need to put the jump starter pack in the frunk. Jumping the two wires behind the tow hook cover will not unlock the car, it just pops open the frunk. You won't be able to get inside the doors or the trunk without jump starting the car.

I've carried my lithium ion jump starter in my frunk for the last 4.5 years. Your jump pack should be rated for hot temperatures inside a car and the temperature in the frunk should not affect it. It should actually get hotter inside the car due to the glass and the greenhouse effect. The frunk will probably not get much hotter than ambient temperature, which should be fine for the jump pack battery.

How often do you need to recharge your jump starter? I’m thinking of doing this but I’m also thinking that when needed it would be out of juice.

 

[android04]

How often do you need to recharge your jump starter? I’m thinking of doing this but I’m also thinking that when needed it would be out of juice.

If I don't use it, I top it off about every year. Never used it on my own car, but I've used it on other ICE cars.

 

[Randy-12]

If I don't use it, I top it off about every year. Never used it on my own car, but I've used it on other ICE cars.

Wow, I thought it would have been once a month. I can easily remember once a year!

 

[JamieFSD78]

Hello,

I let my car sit for 2 weeks while I was on vacay at my friends house near the airport and I came back and my car appears to be bricked. Trunk wouldn’t open unless I pulled it open manually . Couldn’t get in the car other than through the passenger side front door, I can’t switch it into D or R. I saw indications that the low voltage battery was dead so I tried jumping it and didn’t help. The AC and the stereo also wasn’t working. I tried rebooting the car by pressing scroll wheels and brake and that did nothing. My main battery is at 33%. My plan of action tomorrow is to buy a new 12v battery and replace it but in the mean time I’m seeking advice. Any ideas???? Thank you

 

[davewill]

This doesn't exactly sound like a dead LV battery. If you're able to measure the voltage of the LV system, that might be helpful.

However, I think it's time for Tesla service to diagnose, and that's what I'd do.

 

[android04]

Hello,

I let my car sit for 2 weeks while I was on vacay at my friends house near the airport and I came back and my car appears to be bricked. Trunk wouldn’t open unless I pulled it open manually . Couldn’t get in the car other than through the passenger side front door, I can’t switch it into D or R. I saw indications that the low voltage battery was dead so I tried jumping it and didn’t help. The AC and the stereo also wasn’t working. I tried rebooting the car by pressing scroll wheels and brake and that did nothing. My main battery is at 33%. My plan of action tomorrow is to buy a new 12v battery and replace it but in the mean time I’m seeking advice. Any ideas???? Thank you

You can try jumping the wires for the frunk with the new 12v battery. What did you use to try to jump open the frunk? Because many petals jump starters have reverse polarity protection that will keep then from outputting anything unless they detect a small voltage on the two cables. There is no voltage on the Tesla emergency frunk wires, so a jump starter like that would not do anything unless it has a bypass mode.

 

[JamieFSD78]

You can try jumping the wires for the frunk with the new 12v battery. What did you use to try to jump open the frunk? Because many petals jump starters have reverse polarity protection that will keep then from outputting anything unless they detect a small voltage on the two cables. There is no voltage on the Tesla emergency frunk wires, so a jump starter like that would not do anything unless it has a bypass mode.

The battery had enough juice to open the passenger door and frunk when I opened frunk from the screen. Wouldn’t let me put it in drive or reverse . Anyway my car was parked 5 minutes from a Tesla service center and they came and replaced my battery for 117$ the next day cuz my car is over warranty miles. Thank us for your advice.

 

[Resist]

I no longer have my 12 volt lead acid battery Tesla and have one with the new Lithium Ion battery. Can a portable battery jumper still be used with this battery?